A319/320/321

[Chris E]

what are the differences between them, i saw on this last trip alone that i was riding an A319 on one sheet of paper, A320 on another and A321 on another, what are the differences?

[C]

Size. They are all members of the A320 family. The A318 is the smallest (shortest), through to the A321 which is the largest (longest).

You could say its equivalent to how Boeing have the 737-600, 700, 800 and 900 very basically...

[Chris E]

ah, ok, that explains a lot, and one more question on these planes, when you start to taxi you hear odd noises, like someone wiping down the side of the plane, we also heard that noise when we parked and were getting ready to get off, i know i didnt give the best description, but maybe you still know what im talking about, lol, would be good to know that too cause my sister doesnt like to fly and panicks at that sound, lol

[Jimbo]

like someone wiping down the side of the plane

LOL i just found that quite funny the "wiping" part.
I think the sound is just generally due to the engine noises, but im not sure at all, sorry i couldn't be of more help!

Jimbo

[jrpilot]

From a video I saw I think that what you MAY have heard was the pilots checking/turning on/off the Oxygen.

[Craig.]

could have been the flaps. APU shutting down/starting up.

[Felix/FFDS]

You're all wrong - on taxying, the Airbuses go over a portable lavatory cleaning device - the wiping sound you hear is the the wiping of the lavatory dump valves...